790 results
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Journal Article
Spatial variability of hydraulic parameters of a cropped soil using horizontal crosshole ground penetrating radar
Abstract Soil hydraulic parameters (SHP) play a crucial role controlling the spatiotemporal distribution of water in the soil–plant continuum and thus affect water availability for crops. To provide reliable information on the SHP at different scales, measurement techniques with a good spatial…
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Journal Article
Construction of dense CMP data from sparsely collected GPR CMP data for the improved estimation of soil dielectric constant profile
Abstract A multichannel ground‐penetrating radar unit, which consists of multiple fixed transmitters and receivers, allows one to obtain time‐lapse multi‐offset gathers (MOG) by fixing the unit in one place at the expense of spatial resolution. When applying common semblance analysis for dielectric…
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Journal Article
Importance of short‐term variations in greenhouse gas emission and cycling along agricultural riparian zone soils
Abstract Riparian zones and drainage ditch ecosystems are numerous in many agroecosystems throughout the world and provide ecosystem services including carbon sequestration and greenhouse gas (GHG) regulation. These features are important for sustainability goals and GHG accounting to help meet…
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Journal Article
A simple experiment to trace stemflow infiltration: Advantages and challenges of using stable isotopes of hydrogen and oxygen and electrical resistivity tomography
Abstract Stemflow is a key process in forested catchments due to its control on soil water content and nutrients’ transport. However, there are still few studies focusing on stemflow infiltration and relying on direct observations that are minimally invasive and repeatable. In this study, we…
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Journal Article
Applying minirhizotrons to observe spatiotemporal variations in rooting depth and distribution in agroecosystems to improve the performance of hydrological models
Abstract To understand and explain soil moisture dynamics, the role of the vegetation is crucial. Hydrological processes in agricultural soils are strongly affected by rooting depth and root distribution. We present a new approach to monitor and model root dynamics and its influence on soil…
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Journal Article
Modeling tree responses to soil water variability guides irrigation to account for soil winter reserves
Abstract High‐yield almond (Prunus amygdalus) production requires irrigation to support soil water availability throughout the summer. We aimed to develop tools that project almond trees’ water requirements and then integrate them into irrigation management. We postulated that deficit irrigation…
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Journal Article
Organic carbon stocks in weathered bedrock—Establishing the soil parent material as a new horizon in soil carbon research
Abstract Soil organic carbon is essential for sustaining soil health and functioning and for achieving the United Nations Sustainable Development Goals. However, soil carbon research to date has focused predominantly on the surface horizons of soil, with fewer studies accounting for the carbon…
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Journal Article
Self‐potential signals of soil columns experiencing evaporation and transpiration
Abstract The self‐potential (SP) method has been used in hydrological sciences to monitor many hydrologic processes thanks to the electrokinetic coupling between water flow and streaming current in geological materials. Despite many useful applications, quantitative interpretations are still rare…
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Journal Article
Importance of background threshold value development within risk‐based corrective action programs
Abstract Risk‐based corrective action (RBCA) programs employ conservative models to develop default values for soil screening, which simplify the risk assessment process. However, for several naturally occurring metals (e.g., arsenic and lead), these published screening values are often unrealistic…
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Journal Article
Validation of downscaled 1‐km SMOS and SMAP soil moisture data in 2010–2021
Abstract Soil moisture (SM) is an important component for many applications in agriculture, hydrology, meteorology, and ecology. In past decades, passive/active microwave sensors onboard Earth observation satellites are utilized to obtain SM estimates from radiometer or radar observations. In this…
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Journal Article
Microbial mediated carbon and nitrogen cycling in the spatially heterogeneous vadose zone: A modeling study
Abstract Spatially distributed properties of the subsurface result in varying water saturation and preferential flow paths, which lead to heterogeneous solute transport patterns and heterogeneous microbial environments. This, in turn, influences the distribution of nutrients and energy gradients…
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Journal Article
Interpretation of large‐scale, long‐term electrical geophysical monitoring guided by a process simulation
Abstract Surface electrical resistivity tomography (ERT) was used at a waste site to monitor vadose zone changes in electrical properties as a proxy for contaminant flux over a span of 17 years. The BC Cribs and Trenches (BCCT) site at the Hanford site contains 20 disposal trenches and six disposal…
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Journal Article
Transport, dispersion, and degradation of nonpoint source contaminants during flood‐managed aquifer recharge
Abstract In water‐stressed regions of the world, the inundation of working landscapes to replenish aquifers—known as flood‐managed aquifer recharge (flood‐MAR)—has become a valuable tool for sustainable groundwater management. Due to their diverse land use histories, however, many potential…
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Journal Article
Simulation of near‐saturated flow in soil macropores with the lattice Boltzmann method
Abstract Direct information about the soil structure can be obtained with X‐ray computed microtomography, and the imaged macropore networks can be used as geometries in the lattice Boltzmann flow simulations. This method has not been widely applied for near‐saturated flows due to methodological…
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Journal Article
Stochastic analysis of plant available water estimates and soil water balance components simulated by a hydrological model
Abstract The uncertainty in soil hydraulic parameters is often not taken into account in process‐based hydrological modeling. Performing runs with 104 stochastic parameter realizations, we evaluated the propagation of uncertainty in the Van Genuchten–Mualem (VGM) parameters into estimates of the…
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Journal Article
Elucidating the role of water films on solute diffusion in unsaturated porous media by improved pore‐scale modeling
Abstract Solute diffusion in partially saturated porous media is an important fundamental process in many natural and environmental systems. At low water saturation, the solute transport is governed by the diffusion in thin water films on the surfaces of solids. In this study, we established an…
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Journal Article
Estimation of soil moisture using environmental covariates and machine learning algorithms in Cathedral Peak Catchment, South Africa
Abstract Soil moisture (SM) is a fundamental constituent of the terrestrial environment and the hydrological cycle. Owing to its significant influence on catchment hydrological responses, it can be utilized as an indicator of floods and droughts to aid early warning systems. This study aimed to…
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Journal Article
Soil carbon determination for long‐term monitoring revisited using thermo‐gravimetric analysis
Abstract Soils and the vadose zone are the major terrestrial repository of carbon (C) in the form of soil organic matter (SOM), more resistant black carbon (BC), and inorganic carbonate. Differentiating between these pools is important for assessing vulnerability to degradation and changes in the C…
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Journal Article
Effects of improved water retention by increased soil organic matter on the water balance of arable soils: A numerical analysis
Abstract Climate change will lead to prolonged droughts in various regions of the world, which may significantly affect agricultural production. This is particularly problematic for soils with low water retention capacity, which cannot store sufficient water for crops. In this paper, we investigate…
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Journal Article
Linking horizontal crosshole GPR variability with root image information for maize crops
Abstract Non‐invasive imaging of processes within the soil–plant continuum, particularly root and soil water distributions, can help optimize agricultural practices such as irrigation and fertilization. In this study, in‐situ time‐lapse horizontal crosshole ground penetrating radar (GPR)…